1. Field of the Invention
This invention relates to an electronic device, more particularly to an electronic device that includes an internal antenna.
2. Description of the Related Art
FIG. 1 illustrates a conventional electronic device, such as a mobile phone, that includes a casing 11, a circuit board 12, and an internal antenna 13. The circuit board 12 is disposed in the casing 11. The internal antenna 13, which is a planar inverted-Fantenna (PIFA), is disposed in the casing 11, is operable in both 900 MHz and 1800 MHz frequency bandwidths, is generally rectangular in shape, and is formed with a first groove 131 that extends between opposite first and second edges of the internal antenna 13, and a second groove 132 that extends transversely from the first groove 131 to a third edge of the internal antenna 13. A feeding point 133 is provided on the internal antenna 13, and is coupled to the circuit board 12 through a feeding line. A grounding point 134 is provided on the internal antenna 13, and is coupled to an electrical ground provided on the circuit board 12 through a grounding line.
The conventional electronic device is disadvantageous in that, since a relatively large portion of the internal antenna 13 overlaps with the circuit board 12, a considerable capacitance effect, which causes undesirable interference to the transmitted and received signals of the internal antenna 13, is produced. This results in a poor signal quality for the conventional electronic device.